资源简介
linux2.6源码,Linux是一套免费使用和自由传播的类Unix操作系统,是一个基于POSIX和UNIX的多用户、多任务、支持多线程和多CPU的操作系统。它能运行主要的UNIX工具软件、应用程序和网络协议。它支持32位和64位硬件。Linux继承了Unix以网络为核心的设计思想,是一个性能稳定的多用户网络操作系统。
代码片段和文件信息
/*
* arch/alpha/boot/bootp.c
*
* Copyright (C) 1997 Jay Estabrook
*
* This file is used for creating a bootp file for the Linux/AXP kernel
*
* based significantly on the arch/alpha/boot/main.c of Linus Torvalds
*/
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include “ksize.h“
extern unsigned long switch_to_osf_pal(unsigned long nr
struct pcb_struct * pcb_va struct pcb_struct * pcb_pa
unsigned long *vptb);
extern void move_stack(unsigned long new_stack);
struct hwrpb_struct *hwrpb = INIT_HWRPB;
static struct pcb_struct pcb_va[1];
/*
* Find a physical address of a virtual object..
*
* This is easy using the virtual page table address.
*/
static inline void *
find_pa(unsigned long *vptb void *ptr)
{
unsigned long address = (unsigned long) ptr;
unsigned long result;
result = vptb[address >> 13];
result >>= 32;
result <<= 13;
result |= address & 0x1fff;
return (void *) result;
}
/*
* This function moves into OSF/1 pal-code and has a temporary
* PCB for that. The kernel proper should replace this PCB with
* the real one as soon as possible.
*
* The page table muckery in here depends on the fact that the boot
* code has the L1 page table identity-map itself in the second PTE
* in the L1 page table. Thus the L1-page is virtually addressable
* itself (through three levels) at virtual address 0x200802000.
*/
#define VPTB ((unsigned long *) 0x200000000)
#define L1 ((unsigned long *) 0x200802000)
void
pal_init(void)
{
unsigned long i rev;
struct percpu_struct * percpu;
struct pcb_struct * pcb_pa;
/* Create the dummy PCB. */
pcb_va->ksp = 0;
pcb_va->usp = 0;
pcb_va->ptbr = L1[1] >> 32;
pcb_va->asn = 0;
pcb_va->pcc = 0;
pcb_va->unique = 0;
pcb_va->flags = 1;
pcb_va->res1 = 0;
pcb_va->res2 = 0;
pcb_pa = find_pa(VPTB pcb_va);
/*
* a0 = 2 (OSF)
* a1 = return address but we give the asm the vaddr of the PCB
* a2 = physical addr of PCB
* a3 = new virtual page table pointer
* a4 = KSP (but the asm sets it)
*/
srm_printk(“Switching to OSF PAL-code .. “);
i = switch_to_osf_pal(2 pcb_va pcb_pa VPTB);
if (i) {
srm_printk(“failed code %ld\n“ i);
__halt();
}
percpu = (struct percpu_struct *)
(INIT_HWRPB->processor_offset + (unsigned long) INIT_HWRPB);
rev = percpu->pal_revision = percpu->palcode_avail[2];
srm_printk(“Ok (rev %lx)\n“ rev);
tbia(); /* do it directly in case we are SMP */
}
static inline void
load(unsigned long dst unsigned long src unsigned long count)
{
memcpy((void *)dst (void *)src count);
}
/*
* Start the kernel.
*/
static inline void
runkernel(void)
{
__asm__ __volatile__(
“bis %0%0$27\n\t“
“jmp ($27)“
: /* no outputs: it doesn‘t even return */
: “r“ (START_ADDR));
}
extern char _end;
#define KERNEL_ORIGIN \
((((unsigned long)&_end) +
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